EXTENSOR POLLICIS LONGUS
| ORIGIN Middle third of posterior ulna (below abductor pollicis longus) and adjacent interosseous membrane |
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| INSERTION Base of distal phalanx of thumb via Lister's tubercle (dorsal tubercle of radius). |
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| ACTION Extends interphalangeal and metacarpophalangeal joints of thumb |
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| NERVE Posterior interosseous nerve (C7 , 8 ) |